As the age of the multi-media progresses, research on the narrow-pitch multi-pin package of integrated circuits (ICs) or high-density package bare chips is becoming increasingly active. Under such circumstances, the demand for the high-density printed circuit boards with more levels, such as the high-density multi-layer printed circuit boards with line widths of 50 xcexcm and the land diameter of (via) of 300 xcexcm is becoming commonplace.
The fining method has been proposed in a variety of forms, but the B2 IT (Buried Bump Interconnection Technology) is known as a high-density multi-layer printed circuit board having an environment-friendly characteristic and a good cost performance.
In this method, a circuit substrate, comprising a glass-epoxy substrate and a bump provided thereon through a first circuit layer of copper foil, is provided first; then, an interlayer insulating film is laid on the first circuit layer, and a second circuit layer, including a copper foil is laid on the interlayer insulating film; then, the first circuit layer is connected to the second circuit layer by means of thermal pressure welding method. In this case, the bump protrudes through the interlayer insulating film to be connected to the second circuit layer. The bump is formed by the screen printing method.
Incidentally, the wire bonding method is one of the conventional packaging methods of semiconductors. Recently, however, the packaging method by using the bump is becoming popular because of its being suited for high-density packaging.
Similar to the above packaging method, there are the packaging methods by using TAB, flip chip, etc. As such, how to form the bump is the key technology for these methods.
As bump forming methods, the evaporation method, galvanizing method, and screen printing method have been proposed. However, these forming methods have the problems described below. That is, the forming method by using the evaporation method takes too much time to form the bump, which results in a high manufacturing cost. The forming method by using the galvanizing method has a drawback, in that it requires a complex process comprising the processes for resist application, photolithography, and etching in order to provide the openings corresponding to the size and the pitch of the electrodes and forming the bump by the galvanizing method or electroless plating method.
In contrast, the forming method by using the screen printing method is simpler and more economical in terms of the forming process, since the bump can be formed where a mask having an opening corresponding to the bump is laid on the substrate; a paste is applied on the mask; the mask is printed on the substrate by using a squeegee; then the paste is baked to remove the solvent and resin components from the paste, thereby forming the bump.
However, the forming method by using the screen printing method has a problem as described below.
The height of the bump is dependent on the film thickness. The film thickness of the mask cannot be determined freely in relation with the dimensions of the bump due to the limitation arising from the embedding ability and passability of the paste with respect to the opening of the mask. This gives rise to a problem in that the smaller the size of the bump, the lower the height of the bump. Such a problem can be overcome by repeating the screen printing process several times, but this leads to the increase in the complexity of process and forming cost.
FIG. 26 shows the conventional method of position matching between the substrate and the chip.
In this position matching method, first the position of the pad 302 of the substrate 301 relative to any given point (origin) is determined by a camera 303. Similarly, the positions of the chip 304 the bump 305 relative to another origin are determined by a camera 306.
Next, based on these relative positions and the above 2 origins, the substrate 301, chip 304 or the substrate 301 and chip 304 are shifted to match the position of the pad 302 and the position of the bump 305. Then, the chip 303 is pressed against the substrate 301 to effect the bonding between the substrate 301 and the chip 303.
However, this conventional position matching method has a problem as described below. That is, even if the relative positions of the substrate 301 and the chip 304 are determined accurately, mismatching can occur unless the chip 304 is shifted accurately, since the substrate 301 and the chip 304 are primarily separated from each other. This will become a serious problem in the case of a highly integrated chip.
FIG. 27 shows the position matching method between another conventional substrate and a chip.
In this position matching method, first the position of the pad 302 and the substrate 301 relative to any given point (origin) that is determined by the camera 306. Similarly, the position of the bump 305 of the chip 304 relative to the same origin is determined by the same camera 306.
Then, based on the determined positions of the pad 302 and the bump 305, for example, the position of the bump 305 relative to the pad 302 is determined.
Next, the position of the pad 302 is matched with the position of the bump 305 by shifting the chip 304 by the distance corresponding to the above relative positions.
Subsequently, the chip 304 is lowered and pressed against the substrate 301, thereby effecting the bonding between the substrate 301 and the chip 304.
However, this position matching method has a problem given below. In this position matching method, in determining the positions of the pad 302 and the bump 305, since it is necessary to place the camera 306 between the substrate 301 and the chip 304, the distance between the substrate 301 and the chip 304 increases. Therefore, even if the positions of the pad 302 and the bump 305 are known accurately, mismatching occurs unless the chip 304 is lowered accurately at the time of bonding.
FIG. 28 shows the conventional transfer method of the substrate or the chip.
In this transfer method, a transfer system 311 having a vacuum suction system is used. The substrate or the chip 312 is carried while being held by the transfer system 311 by means of the vacuum suction.
However, this conventional transfer method has a problem given below. That is, the large suction force acting selectively and partially acting on the substrate or the chip 312 causes the deformation or break of the substrate or the chip 312.
An object of the present invention is to provide a semiconductor device having a construction permitting easy formation of a necessary bump having a necessary shape, a pattern forming method permitting the formation of a pattern such as the pattern of the bump and the like and a pattern forming device.
Another object of the present invention is to provide a manufacturing method of a semiconductor device capable of preventing the positional mismatching between two members to be matched with each other at the time of the matching or the positional mismatching of the two members to be matched at the time of the connection thereof after the previous matching and a matching mark to be used therefore.
Another object of the present invention is to provide a semiconductor manufacturing method including a process for enabling a substrate or a chip to be transferred free of damage to such substrate or chip.
The semiconductor device according to the present invention is characterized by being provided with a bump including a magnetic substance. Further, in order to form the bump having such a property, the manufacturing method of the semiconductor device according to the present invention is characterized by comprising at least a process for selectively laying a conductive paste onto the substrate and a process for forming a bump including the conductive paste by letting it rise by an external field including the magnetic field of the conductive paste.
In the case of the bump having the structure described above, a bump having a necessary shape (with sufficient height and satisfactory embeddability) can be formed easily.
Further, the semiconductor device manufacturing method according to the present invention is characterized by comprising a process for placing a second matching member, having a second magnetic substance as a second matching mark, above a first matching member, having a first magnetic substance as a first matching mark, a process for detecting the magnetic field produced by the first and the second magnetic substances, a process for determining the positions of the first and the second magnetic substances based on the magnetic field, a process for effecting the matching of the first matching member and the second matching member and a process for connecting the first matching member and the second matching member.
Further, the semiconductor device manufacturing method according to the present invention is characterized by comprising a process for placing the second matching member, with the magnetic substance as the matching mark, above the first matching member, a process for detecting the magnetic field produced by the magnetic substance, a process for matching the first matching member with the second matching member according to the position of the determined magnetic substance and the previously determined position of the first matching member and a process for connecting the first matching member with the second matching member.
With the semiconductor device manufacturing method as is described above, the matching of the first matching member and the second matching member can be made with the matching members kept very close to each other, so that the mismatching between the first matching member and the second matching member at the time of the positional matching and the positional mismatching when connecting the first matching member with the second matching member can be prevented.
Further, another semiconductor device manufacturing method according to the present invention is characterized by comprising a process for providing a holding member with a magnet, a process for holding the substrate or the chip, having the magnetic substance, by the holding member by the magnetic force and a process for transferring the holding member.
In the case of the semiconductor device manufacturing method as is described in the foregoing, the magnetic field produced between the holding member and the substrate or the chip (member to be transferred) is distributed substantially evenly, thereby preventing a large force from acting partially on the member to be transferred. Thus, according to the present invention, the member to be transferred can be transferred without damaging the member to be transferred.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.